A dynamic virtual memory management under real-time constraints

摘要

In this work we describe a new memory management concept which allows the use of both virtual and dynamic memory management at the same time in the context of real-time systems. For a fixed size of the virtual address space, the operations of memory allocation, de-allocation and access have a constant complexity. Therefore our approach is highly suited for real-time environments with hard deadlines. We employ efficient data-structures to yield runtimes that are close to traditional static memory management concepts, and - at the same time - provide the user with the full flexibility of both virtual and dynamic memory management. Our approach is based on novel operating system components and a novel real-time aware virtual memory management unit (RTMMU) in hardware. Our experimental results demonstrate the applicability of our concept and compare its performance with a classical approach. The results show that our new approach does not only provide constant-time memory management operations, but is also able to reduce the memory footprint to a large extent.